Defoaming composition and process



R. H. LARSEN y DEFOAMING COMPOSITION AND PROCESS Filed Jan. 19, 1942 Was/7 51u99/ wa/erw-f//fra//on 7 [ancenrah'on by Vacuum evapora /'on L j-Z@ F-D l [2a Vacuum pazr'l` Lil/29 Vacuum pan Vacuum pan A70/asse:

INV-ENTOR ,Pudo/,0b /lars en E" @gmbh ATTORNLY iid,

. 2,412,276 Y v nsroAMiNG comosrrrousnnrnooass 4 f Rudolph E. Larsen, San Francisco, Calif., assignor-to Fred Bresee, Jr., doing business as- "Balab, Hillsborough, Calif.

` Application January 19,1942. smal No. 427,305

EClaims.

This invention relates generally to, compositions and processes for eliminating foam and for suppressing. its formation inthe sugar industry. A

used in sumcient amounts to control foam formation to a substantial degree.

It is an object ofthe vpresent invention to provide a composition which will effectively eliminate or kill foam in liquors undergoing treatment in sugar manufacturing processes, and which will also have a sustained action in suppressing formation of foam. 4

lAnother object of the invention is to provide a defoaming process which can be used in the presence of lime, without giving an undesirable soep reaction or saponiiication.

A further object of the invention is to provide a defoaming composition and method which can be used to advantage in sugar-containing liquors being subjected to vacuum evaporation.

Further objects. of the. invention will appear from the following description in which the pre ferred embodiment has been set forth in'detail in conjunction with the flow sheet.

My defoaming composition consists-of a fatty acid together with a hydrocarbon. The fatty acid is preferably of vegetable origin, as for example one obtained from soy bean, cocoanut, or corn oil. Such fatty acids are produced as by-products in the refining of 'vegetable oils. For example, in the reiningof such oils to free them of their fatty acid content, it is customary to react the fatty acid content with sodium hydroxide, and to separate out the precipitate which is termed "fatty oil foots 'I'he soap content of the foots is then broken down by reaction with sulfuric acid, after which the resulting fatty acid is washed to free itof any remaining mineral acid content. rThe commercial by-product obtained in this fashion contains from 50 to 60% free fatty acid,

and is free of glycerin. Usable fatty acids can also be obtained as by-products in the hydrogenation process for the rening of vegetable oils, or

2 unsaturated hydrocarbon, and particularly one obtained from a naphthenic, asphaltum or -paraiine base, or combinations Yof the same.

Commercial products of this character are avail-- able on the market, and are known by various names including unsaturated extract oil and lube oil extract. such as white oil can be mixed with the fatty acid and used with some eiectiveness, but not with the effectiveness of unsaturated hydrocarbone.

In general, various proportions and I have secured good results by using from to 40% by weight of the commercial fatty acid product, together with from 'l0 to 60% of vthe unsaturated hydrocarbon product. The two materials are freely miscible.' although they do not appear to enter into chemical reaction.

4In using the composition described above. small quantities are continuously added to the liquors undergoing treatment at various points in the sugar manufacturing process. The points at which the composition is introduced will depend upon the particular plant process employed. One operation to which the composition can be applied to advantage, and which is utilized in all.

modern sugar plants, is the liming and carbonating of the sugar j uice preparatory to filtering the material. Relatively small amounts of the composition introduced at this point suffice to eliminate or hill foam and to suppress foam formation during the subsequent filtering operation. Sulfurizing operations such as are4 employed for decolorizing sugar Juice or sirup are also subject to foaming. Here again the composition can be used to advantage to eliminate foam difficulties during such treatment and during subsequent clarification by filtration. Small additions of the composition can also be made immediately before and during concentration by vacuum evaporation. For example, small amounts can be continuously added to the juice entering the rst effect of the evaporating equipment, and to sirup entering the subsequent effects, -or occasionally added as needed. It has been observed that when my composition is added in this fashion, it not only tends to prevent and suppress foam formation, but in addition it serves to minimize formation of troublesome scale upon the evaporating tubes. In this connection it should be noted that compositions Whichhave been used in the past, such as cocoanut oil, do not tend to lessen scale formation in the evaporator, and in fact seem to aus* ment troublesome accumulation of solids upon the evaporator tubes by ,formation of calcium Saturated hydrocarbon oils can be used,

soaps. Such calcium soaps are not formed when my composition is employed. Foaming can be prevented in the vacuum pans Where the sirup is further concentrated by using the composition as described.

In diierent plant processes operations to which the composition is introduced depend somewhat' upon the particular procedure employed and upon the type of sugar juice being treated. In order to indicate one practical way of using the composition, the drawing shows a typical iiow sheet for a plant process for`beet sugar. To briefly outbonation 14,. 'and` again to filtration l5. For

decolorizing; the juice isv then subjected to the sulfurizing/operation I8,- -where it is contacted with sulfurl dioxide gas,vafter which it is again subjected to filtration l1. The purified and decolorized juice isnowfsubjected to vacuum evaporation at I8, by use of multiple effect vacuum evaporators.

Following.concentratiom-the sirup is subjected to further. sulfurizing treatment I9, after which it is filtered .at 2l, and, then sent to the first crystallizing vacuum pan 22. After further concentration'in this treatment, with partial crystallization ofthe sugar, the material is subjected ing treatment of sugar syrup,iconsisting of from.

about 30 to 40% of a fatty acid, the fatty acid to centrifugin'g 23, which removes the crystal# lized sugar.' The remaining sirup. is treated in the second-vacuum pan 2|, and after further centrifuging at 25, the remaining sirup is sent to the third vacuum pan 26. Final centrifugi'ng 21 of the sirupfrom the last vacuum pan yields `molasses and sugar which is mixed back at 28 with the sirup entering the vacuum pan 24. Sugar-from centrifuging 25 is also mixed back at 29 with the Sirup entering vacuum pan 2,2.

'Points of introduction of the composition described above have been indicated in the flow sheet and designated by letters A'to G inclusive. 'I'hese points of introduction are as follows:

In certain sugar plants the molasses is subjected to further treatment known as the Stef-4 fen" process, in whichthe molasses is diluted and limed, heated, and precipitated tricalcium sucrate removed` in a filter. The sucrate is then returned to the. main process. Foaming in this process con also belalleviated by additions of small amounts of ymy composition.

In the above ow sheet a total consumption oi 6.9 gallons of my composition was employed each twenty-four hours, where 800,000 pounds of sugar was being manufactured from 297 tons per hour of the raw beet juice. This total amount was distributed fairly equally between the different points of introduction, including the Stenen process, and was introduced by use of suitable feeding devices capable of adding the material by drops at a regulated rate.

`The plant process described above and as shown in thefiow sheet gave considerable difdculty with foam formation when using such deioaming ma'- terials as cocoanut oil.y These diculties were completely overcome bythe use of my compost tion and process. In addition, my process re= sulted in an economy with respect to the amount of defoaming composition required, and a marked betterment in general operating efficiency was v noted.

I claim: 1. A defoaming composition for sugar syrup v.comprising a fatty acid of vegetable oil origin,

the fatty acid being free of glycerine and ob.. tained by removal from foots resulting from the 'refining of vegetable oil by treatment with alkali and subsequent acidulation with sulphuric acid, together with an' unsaturated extract oil `of mineral oil origin.

2. A composition for suppressing foaming durbeing free of glycerin and obtained by removal from foots resulting from` the refining of vege- 'table oil by treatment with alkali and subsequent acidulation with sulphuric acid, together with from about '70 to 60% of an unsaturated extract oil of mineral oil origin.

3. In a process for suppressing foaming during treatment of sugar syrup, introducing into thesugar syrup a mixture comprising afatty acid, the fatty acid ybeing free of glycerin and involving intermixing of the syrup or juice with lime followed by carbonation of the mixture and filtration of the carbonated material, the improvement consisting oi' suppressing foam formation 4by introducing into the syrup a mixture comprising a fatty acid of vegetable oil origin, the

v fatty acidbeing free of glycerin and obtained by removal from foots resulting from the refining of vegetable oil by treatment with alkali and subsequent acidulation with sulphuric acid, to gether with an unsaturated extract oil of min eral oil origin, the amount introduced being in sufiicient to cause contamination of the sugar.

5. A defoaming composition consisting oi a glycerine free fatty acid of vegetable oil origin together with an unsaturated extract oil of min- 

